getchar() returns the first character in the input buffer, and removes it from the input buffer. But other characters are still in the input buffer (\n in your example). You need to clear the input buffer before calling getchar() again: void clearInputBuffer() // works only if the input buffer is not empty { do { … Read more
Because you typed ‘a‘ and ‘\n‘… The ‘\n‘ is a result of pressing the [ENTER] key after typing into your terminal/console’s input line. The getchar() function will return each character, one at a time, until the input buffer is clear. So your loop will continue to cycle until getchar() has eaten any remaining characters from … Read more
You need to hit Enter and then use ctrl+Z and then Enter again. or, you may also use F6
The input is only sent to the program after you typed a newline, but scanf(“%s”, command ); leaves the newline in the input buffer, since the %s(1) format stops when the first whitespace character is encountered after some non-whitespace, getchar() then returns that newline immediately and doesn’t need to wait for further input. Your workaround … Read more
Unlike some other languages you may have used, chars in C are integers. char is just another integer type, usually 8 bits and smaller than int, but still an integer type. So, you don’t need ord() and chr() functions that exist in other languages you may have used. In C you can convert between char … Read more
Yes, you have to consume newlines after each input: char1 = getchar(); getchar(); // To consume `\n` char2 = getchar(); getchar(); // To consume `\n` This is not compiler-dependent. This is true for all platforms as there’ll be carriage return at the end of each input line (Although the actual line feed may vary across … Read more
This code can be written more clearly as: main() { int c; while (1) { c = getchar(); // Get one character from the input if (c == EOF) { break; } // Exit the loop if we receive EOF (“end of file”) putchar(c); // Put the character to the output } } The EOF … Read more
How to clear stdin before getting new input? .. so I need something with the same functionality. With portable C this is not possible. Instead suggest a different (and more usual C) paradigm: Insure previous input functions consumes all the previous input. fgets() (or *nix getline()) is the typical approach and solves most situations. Or … Read more
On Unix-like systems (at least by default), an end-of-file condition is triggered by typing Ctrl-D at the beginning of a line or by typing Ctrl-D twice if you’re not at the beginning of a line. In the latter case, the last line you read will not have a ‘\n’ at the end of it; you … Read more
The terminal driver doesn’t return anything until you hit return, even if the read() operation would accept what’s already there. To get character-by-character input from a terminal, you have to get it out of canonical mode into raw or cbreak mode, and that requires different operations altogether. Take a look at the POSIX manual on … Read more